The air conditioning may typically maintain an indoor state suitable for an indoor use purpose by simultaneously adjusting indoor temperature, humidity, ventilation, air, cleaning, and the like. The air conditioning apparatuses may include air conditioners, air cleaners, and the like.
The air cleaners may be an apparatus used to reduce pollutants contained in the indoor air, and a usage amount of the air cleaner has been increasingly increased as concerns on various allergies or diseases due to fine dust are increased in recent years.
The air cleaners may be divided into a filter type, an ionic type, an electrostatic precipitation type, and a water filter type. The filter type may be a mainstream type among the air cleaning types, and the filter type air cleaner may suck air into an air cleaner main body using a fan, purify the polluted air through a filter provided in the inside of the main body, and discharge the purified air to the outside of the main body. The filter type air cleaner may typically employ a method which collects and filters particles in the air using the high efficiency particulate air (HEPA) filter and adsorbs odor using activated charcoal. The products which employ both the filter type and the electrostatic collection type using a plasma effect have been shipped. Other than the activated charcoal, the titanium dioxide photocatalyst may be employed or the ultra low penetration air (ULPA) filter which is a finer filter than the HEPA filter may be employed.
The air cleaners may detect a dust concentration of the air through a dust sensor provided in the inside of the main body and adjust air purification speed by determining a pollution level of the indoor air based on the detected dust concentration.
FIG. 1 illustrates a dust sensor 1 provided in a main body of an air cleaner. The dust sensor 1 may include a light emitter 5 and a light receiver 7 in a housing 3. An air inlet (not shown) and an air outlet 3a which the air flow in and out therethrough may be formed in a front and rear of the housing 3.
The operation of detecting the dust concentration using the dust sensor 1 will be described below. First, light is irradiated toward the air, which flows in the housing 3 through the air inlet, through an infrared light emitting diode (LED) 5a of the light emitter 5. The dust concentration (or the amount of dust) contained in the air may be determined by detecting the amount of light reflected from dust particles P contained in the air through a photo diode of the light receiver 7 and counting a scattered light pulse per unit hour.
In response to the air cleaner which is stored in an outdoor warehouse being installed indoor in the wintertime, dew condensation may occur in surfaces of lenses 5b and 7b provided in the light emitter 5 and the light receiver 7 of the dust sensor 1 due to an abrupt difference between the indoor and outdoor temperatures.
In response to the air cleaner being operated in a state that the dew condensation is formed in the surfaces of the lenses 5b and 7b, the light emitted from the infrared LED 5a of the light emitter 5 is reflected from a plurality of water droplets in the surfaces of the lenses 5b and 7b and thus the amount of light flowing in a light-receiving sensor 7a of the light receiver 7 may be significantly increased.
Accordingly, since it is determined that the dust concentration detected through the dust sensor 1 is high until the water droplets formed in the surfaces of the lenses 5b and 7b are naturally vaporized and removed from the surfaces of the lenses 5b and 7b, the consumers may misunderstand that the use environment (for example, a place in which the air cleaner is installed) is polluted or may determine that the dust sensor is defective, and thus consumer complaints may be increased due to performance degradation of the air cleaner.